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<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>常量/只读变量的使用</title>
  <script type="text/javascript">

    //常量
    const PI=3.14
    //PI=3.1415926  //报错，const修饰的不能修改
    console.log("PI=",PI)

  </script>
</head>
<body>

</body>
</html>